As an example of sensor-equipped display devices, a capacitive sensor capable of detecting contact or approach of an object, based on a change in the electrostatic capacitance, has been recently developed. Detection electrodes and sensor drive electrodes constituting such a sensor are disposed in a display area where an image is displayed, and opposed to each other with dielectrics interposed between the electrodes. The detection electrodes are electrically connected to lead lines located outside the display area.
Demands for downsizing of the display device are increased while the display area is extended, and the periphery outside the display area tends to become a narrow frame. For this reason, sensor drive electrodes are often disposed closely to lead lines. In this case, the lead lines are considered to function as sensors by capacitive coupling between the sensor drive electrodes and the lead lines.